A conventional public switched telephone network ("PSTN") is formed by routing trunks or lines between various switching systems. The switching systems are often physically grouped together to form a central office. A central office may connect any combination of lines and trunks, and therefore can by used in local switching systems (for interconnecting lines and trunks) and network switching systems (for interconnecting trunks). For purposes of simplicity, only a local switching system for interconnecting lines and trunks will be further discussed.
Often, a single central office switches literally hundreds or thousands of lines. The central office therefore must arrange the switching hardware in a logical manner so that it may be readily accessed, serviced, or replaced. A typical central office will be housed in a multi-floor building, each floor including several rows of switch frames, each switch frame including several shelves of line cards, and each line card serving multiple lines.
Because of the multiplicity of components in a central office, it is often very difficult to find a particular line card to access, service, or replace. To relieve this difficulty, several solutions have been implemented to help identify the location for each line card in a central office. One solution is to manually update a written or computer record of each card and its location. However, this solution suffers from human errors inherently obvious. Another solution is to provide line cards that include specialized circuitry to identify the frame to which they are connected and report this identification to a central data processor through one of the data networks used by the central office. However, this solution also has drawbacks. For one, the card-to-frame identification is only a partial description of the card's location. The location of the card inside the frame, as well as the location of the frame in the central office, are needed to further locate the card. Also, there may exist different manufacturers for line cards, some of which may not provide the above described specialized circuitry. Furthermore, such specialized circuitry can not be readily adapted to existing cards as well as to new cards that do not have the circuitry. Further still, for various reasons, it may not be desirable to utilize any of the data networks in the central office.
Therefore, what is needed is a system and method that provides an exact location of a line card inside a central office.
Furthermore, what is needed is a system and method that can be easily adapted to new as well as existing line cards.
Further still, what is needed is a system and method that can operate without having to use an existing data network.